Auxiliary locking spring equipped tamper-proof padlock



D. J. FOOTE 3,423,969

PROOF PADLQCK Jan. 28, 1969 AUXILIARY LOCKING SPRING EQUIPPED TAMPER Filed June 22, 1967 INVENTOR DANIEL J- FOOTE ATTORNEYS n v United States Patent O 6 Claims ABSTRACT OF THE DISCLOSURE The spring-urged locking lever of a padlock normally projects into the shouldered recess in a shackle leg of the padlock to hold the shackle in its locked condition. To prevent the contingency of a tamperer unauthorizedly retracting the locking lever by forcing or jarring it inwardly by foreign pressures applied while the padlock is closed and locked, there is provided a separate and auxiliary locking spring, cam or wedge operated, which auxiliary locking spring is positioned below the regular locking lever and has a pair of legs which engage in shouldered recesses in the long leg of the padlock shackle to provide additional or auxiliary locking and holding strength between the locking lever and the engaged shackle. The mutilated inner end portion of the key-operated cylinder of the lock carries a wedge or cam which, when the cylinder is key operated to yieldingly withdraw the locking lever from the shackle leg notch for shackle-releasing purposes, spreads the legs of the auxiliary locking spring out of the shackle leg notches for shackle-releasing purposes.

BACKGROUND OF THE INVENTION Field of the invention Padlocks of pin, lever, or disc tumbler type incorporate a shackle inserted into openings in the body or case of the padlock, which shackle is normally held in its closed position by a spring loaded locking lever which usually engages in a shouldered recess in the short leg or toe of the shackle. Inasmuch as the holding power of the lock shackle depends upon the extent of its engagement with the locking lever, or by the strength of the lever, the instant invention seeks to prevent burglars, thieves, or tamperers from unauthorizedly releasing the locking lever from the shackle toe notch through the use of tools or bars to force or pry open the padlock shackle, or by the application of force or pressure against the padlock body, or by the insertion of a shim or other tool into the shackle receiving opening in the padlock case to force back the locking lever to its retracted position, or by the insertion of a pick or wire into the cylinder keyway slot to push back or release the leg locking lever. These unauthorized practices are prevented in the instant invention by the inclusion of a separate or auxiliary locking spring positioned in the padlock body below the regular locking lever and having legs engaging in shouldered recesses in the long leg of the shackle so that the shackle cannot be released and projected outwardly even if the regular locking lever is subjected to successful tampering and release. The extra l-cking effect of said auxiliary spring is automatically overcome during normal turning movement of the padlock cylinder by an inserted key through wedge or cam means carried by and turned with the cylinder extension to spread the legs of the auxiliary spring and remove them from their engagement within the shouldered recesses in the long leg of the padlock shackle.

Description of the prior art As far as applicant is aware there is nothing presently available which is similar in any respect to his invention in the provision of an auxiliary locking spring to augment the locking effect of the regular locking lever, together with turnable cam or wedge means to release the holding effect of the auxiliary locking spring. Prior Patents Nos. 2,824,439, 2,842,950 and 2,893,231 are all concerned with means for rendering the locking lever of a padlock relatively tamper-proof, but these prior art patents, as well as other arrangements in the prior art, are devoid of applicants auxiliary locking spring which functions in addition to the normal locking lever.

SUMMARY OF THE INVENTION The present invention provides, in a shackle equipped padlock, an auxiliary locking spring together with a cam or wedge means for operating the same, all of which are independent of the standard locking lever. Said auxiliary spring provides additional locking and holding strength for the padlock shackle and is located within the padlock body in an inaccessible position, and may be formed in sizes and types adaptable to various forms of padlocks. The present invention provides cylinder, lever or disc tumbler padlocks with additional security by affording double latching, and nullifies the danger of having the padlock shackle released by retraction of the leg locking lever through a wire or pick inserted into the keyway slot and further eliminates the possibility of releasing the padlock shackle through the insertion of a shim or the like into the shackle opening to engage and retract the latching lever. Moreover, the double latching afforded by the auxiliary lock spring will prevent the lock from being unauthorizedly opened by blows or pressures imparted to the padlock body which might jar the regular spring loaded latching lever out of its shackle notch engagement.

Another feature of the invention is that the auxiliary locking spring and its operating cam or wedge can be included in a padlock without complicating the ordinary manufacture and assembly thereof, nor add materially to the cost.

Still further objects of the present invention are to provide an auxiliary locking spring equipped tamperproof padlock which is strong, durable, and effective; which increases the utility, performance and safety of the padlock; and which is well adapted for the purposes described.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing, wherein the same reference characters designate the same or similiar parts in all of the views:

FIG. 1 is a vertical sectional view through a laminated padlock provided with the improved auxiliary locking spring mechanism, a portion of the lock cylinder being broken away and in section;

FIG. 2 is a horizontal sectional view through the padlock body or case immediately below the improved auxiliary locking spring and looking upwardly to show the spring and a wedge type of releasing means;

FIG. 3 is a fragmentary detail sectional view through a portion of the long leg of the padlock shackle, taken approximately along the line 3-3 of FIG. 1, and showing the engagement of the auxiliary spring with shouldered recesses in said shackle leg;

FIG. 4 is a side edge view of the auxiliary locking spring;

FIG. 5 is a horizontal sectional view similar to FIG. 2 only showing an alternative form of spring lock releasing means, in the form of a cam, carried by the mutilated end of the cylinder; and

FIG. 6 is a plan view of the cam type of auxiliary spring lock releasing means shown in FIG. 5 and carried by the mutilated inner end of the cylinder.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS Although the invention is not to be restricted thereto, for purposes of illustration the padlock body or case is of laminated construction and is built up of a plurality of superimposed, secured-together plates or laminations 11 provided internally with partitions and walls to define cavities for certain of the lock mechanism. Housed within cavities within the body or case 10 are a spring-loaded leg-locking lever 12 and a key-operated cylinder 13 having a mutilated inner end portion 13' which is adapted to engage and reciprocate the locking lever 12 under the action of a proper key 14 inserted into the keyway in the cylinder 13. While the padlock illustrated is of the pin type, it could, within the scope of the present invention, be of any conventional type (pin, lever, or disc tumbler). Also, the case 10 could be of solid construction.

Regardless of the form of the padlock case, it is provided with a pair of spaced-apart, longitudinally-extending shackle leg receiving openings 15 and 16 which open through the top plate of the padlock casing, and which longitudinally movably receive, respectively, the short leg or toe 17 and the long leg 18 of the padlock shackle 19. The short leg or toe 17 of the padlock shackle at its inner end is provided with a shouldered notch 20 which is engaged by the free end portion of the spring-urged locking lever 12 for shackle locking purposes.

Within a suitable cavity within the padlock case and forming one of the laminations of the case, is an auxiliary spring retainer plate 21, a lower portion of which is recessed to receive the auxiliary locking spring, generally indicated by the numeral 22 and which will be referred to in more detail hereinafter. That portion of the spring retainer plate 21 which extends toward the free end of the shackle toe 17 is formed as a downwardly flanged ring 23 to receive the circularly closed end portion 24 of said auxiliary spring 22. The auxiliary spring 22 is of bifurcated formation and is shaped as is best shown in FIGS. 2, 4 and 5, having a mid portion 25 which is substantially diamond-shaped and extending therefrom, toward the long leg 18 of the shackle, are a pair of rectilineal, laterally-spaced-apart spring legs 26. In registry with said spring leg 26 there are, in an intermediate portion of the long leg of the shackle 18, opposite shouldered recesses 27 in which the end portions of said spring legs 26 normally lodge when said spring is performing its auxiliary shackle locking function.

In order to spread the legs 26 of the auxiliary spring 22 out of the recesses 27 in the long leg of the shackle 19, a spring spreader is provided which may take one of several forms. As shown in FIGS. 1 and 2, this spring spreader may take the form of a quadrilateral wedge 28 having a pair of parallel sides joined by angularly related sides of which side 29 is a long side lying adjacent a flat face portion of the multilated end portion 13' of the cylinder 13. This wedge type of spring leg spreader is, of course, mounted for movement in a path controlled by an upstanding lug 30 on the wedge which extends into a slot 31 therefor in the plate 21.

In lieu of the wedge 28 the spring spreader may also take the form of a cam 28' shown in detail in FIGS. 5 and 6 and whose body portion is formed with a semicircular recess to receive the mutilated end portion 13 of the cylinder 13, so that the cam type of spreader is directly turned by the cylinder when the latter is turned by a key 14 inserted into the cylinder keyway.

Regardless of the form which the spring spreader may take, it is obvious that its engagement with the mutilated end portion 13 of the cylinder will cause the spreader 28 or 28' to be moved, when the cylinder is turned, so as to forcefully bear against portions of the diamond mid section 25 of the auxiliary spring 22 which enclose the spreader 28 or 28'. Thus, the legs 26 of the auxiliary spring 22 may be spread to move the same outwardly of the shackle notches 27 and free the spring of engagement with said shackle leg. Also, the turning movement of the key 14 within the cylinder causes the rounded portion of the cylinder end 13' to contact a depending shouldered portion of the locking lever 12, as is customary, to reciprocate the locking lever 12 toward the left relative to FIG. 1 and remove the nose end of the locking lever from the shouldered notch 21 in the shackle toe 17. Pursuant to the present invention, therefore, the cylinder 13 turned by the key 14 not only causes the locking lever to release the toe of the shackle in the normal manner, but also releases the legs 26 of the auxiliary spring from the long leg of the shackle so that the shackle can be reciprocated outwardly and remove the shackle toe from its case opening 15 for padlock releasing purposes.

A reverse turning movement of the cylinder 13 imparted by the key 14 will return the spring spreader 28 or 23' to its normal position shown in the drawings. When the lock shackle 19 is pushed back into its case openings 15 and 16 the natural contraction of the auxiliary spring legs 26 will automatically engage the same in the shackle leg notches 27 and the spring-loaded locking lever 12 will again engage in the notch 20 in the shackle toe 17, thus accomplishing locking of the padlock shackle.

From the foregoing it will be obvious that the present invention provides an auxiliary locking spring which is entirely independent of the normal shackle toe locking lever, thus providing additional locking and holding strength for the closed padlock shackle. It adds to the security of the padlock shackle locking device by affording dual latching, and even though unauthorized attempts are made to retract and release the locking lever from the shackle toe by any of the known means heretofore recited, the spring-urged legs of the auxiliary locking spring 22 will remain in engagement with the long leg of the shackle so that the shackle cannot be unauthorizedly recipro'cated outwardly for shackle-releasing purposes.

The improved auxiliary locking spring equipped tamper-proof padlock is free of manufacturing and operational complications, is of simple and novel construction, and is well adapted for the purposes described.

What I claim is:

1. In a padlock, a shackle movably extending into the padlock case and having a pair of legs, one of which is reciprocatable free of the case and whose end portion is formed with a locking lever receiving notch, and the other of which is formed with opposed shouldered recesses; a key-operated cylinder within the padlock case and having a mutilated inner end portion; a spring loaded reciprocal locking lever projecting into the first-mentioned leg notch, the mutilated end portion of the cylinder being engageable with said locking lever to retract the latter upon turning movements of the cylinder mutilated end portion; an auxiliary spring within the case and having a pair of yielding legs normally engaging opposite sides of the second shackle leg within its opposed shouldered recesses; and a movable spring spreader operated by a turning movement of the cylinder mutilated end to yieldingly spread the spring legs out of said leg recesses.

2. A padlock as claimed in claim 1 wherein the auxiliary spring has a frame-like mid-portion which encloses the movable spring spreader and is outwardly flexed by a turning movement of the latter.

3. In a padlock, a shackle movably extending into the padlock case and having a pair of legs, one of which is reciprocatable free of the case and whose end portion is formed with a locking lever-receiving notch and the other of which is formed with a shouldered recess; a key-operated cylinder within the padlock and having a mutilated inner end portion; a spring loaded reciprocal locking lever projecting into the first-mentioned leg notch, the mutilated end portion of the cylinder being engageable with said locking lever to yieldingly retract the latter when the multilated end portion of the cylinder is turned; an auxiliary spring within the case formed with a leg normally engaging a side of the second shackle leg within its shouldered recess; and a movable spring leg deflector operated by a turning movement of the cylinder mutilated end to yieldingly deflect the spring leg out of said shackle leg recess.

4. A padlock as claimed in claim 3 wherein the spring deflector is in the form of a Wedge mounted for contact with a portion of the spring to spread the leg thereof, said wedge being engaged by the cylinder mutilated end and moved by a turning movement of the latter.

5. A padlock as claimed in claim 3 wherein the spring deflector is in the form of a cam carried by the cylinder mutilated end.

6. A padlock as claimed in claim 3 wherein the locking lever is retracted from the first leg notch conjointly with the deflection of the auxiliary spring leg.

6 References Cited UNITED STATES PATENTS 479,414 7/1892 Fraim 70-38 1,837,071 12/1931 Sabo 70-38 2,673,458 3/1954 Schlage 7038 2,691,288 10/1954 Childs 7038 FOREIGN PATENTS 480,807 3/1938 Great Britain.

MARVIN A. CHAMPION, Primary Examiner.

EDWARD J. MCCARTHY, Assistant Examiner. 

